N. Korea says can arm long-range missiles with nuclear warheads

North Korea ramped up its nuclear threats on Wednesday, boasting of its ability to deliver miniaturised warheads on high-precision long range rockets — a claim denied by the United States. At the same time, the North denounced “reckless” remarks made in Seoul this week by US Secretary of State John Kerry, and cancelled an invitation to UN Secretary General Ban Ki-Moon to visit a joint industrial zone on its side of the border with South Korea. Pyongyang has been flexing its advancing military muscle of late, most recently announcing it had successfully test-fired a submarine-launched ballistic missile (SLBM).